Electric circuit interrupter and disconnecting device



Dec. 31, 1946. a. R. HERMANN 3 9 ELECTRIC CIRCUIT INTERRUPTER ANDDISCONNECTING DEVICE Original Filed Dec. 13, 1941 I 2 Sheets-Sheet Fig.Z;

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E 16 f 2a 7 Inventor;

Benjamin Rfiermahh,

by WW jwwi I His Atcornew Dec. 31, 1946. R H M 2,413,5G3

ELECTRIC CIRCUIT INTERRUPTER AND DISCONNECTING DEVICE Original FiledDec. 13, 1941 2 Sheets-Sheet 2 Inventor:

I l i I I I I L His Attorngl Ben 'amin R Hermann.

I Patented Dec. 31, 1946' ELECTRIC CIRCUIT INTERRUP L'EB ANDDISCONNECTING DEVICE Benjamin B. Hermann, Lanesborough, Mass, assignorto General Electric Company, a corporation of New York Originalapplication D 1943, Serial No. 190,824

ecember 1s, 1941,Serial a...

422,901. Divided and this application June l i,

6 Claims.

My invention relates to electric disconnecting devices and moreparticularly to a disconnecting device which may be readilyinterchangeable with a fuse device.

This application is a division of my application Serial No. 422,901,filed December 13, 1941, entitled Electric circuit interrupter anddisconnecting device, and assigned to the same assignee as th presentinvention.

Many forms of fuse cutouts have been sug gested heretofore forprotecting electric circuits or controlling electric circuits. Devicesof this sort commonly have a housing provided with a front opening witha cover hinged to the housing for closing this front opening. Usually apair of terminals or contacts are mounted within the housing and thefuse tube is mounted on the cover and provided with contacts to engagethe contacts or terminals in the housing when the cover is closed. Suchcutouts are also provided with indicating means and, upon operation ofthe fuse device, movement of the fuse tube or of the cover or of boththe cover and the fuse tube results.

My invention is concerned with an electric cutout and disconnectingdevic for interrupting larger blocks of power than such devices havebeen commonly used for heretofore. I

Accordingly, it is an object of my invention to provide a new andimproved cutout and disconnecting device combination for controllinglarger blocks of power than such devices have commonly been used forheretofore.

A further object of my invention is to provide a new and improved cutoutdevice which may readily be converted to a disconnecting device, whichtakes up a small amount of space, provides wide separation between thecontacts, and gives an indication of the condition of the circuit while,at the same time, remaining protected against the weather, such as ice,snow, or rain.

Further objects and advantages of my invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to theaccompanying drawings in which Fig. 1 is a side sectional view of myimproved fuse cutout with the fuse intact and the cutout .in the closedposition, Fig. 2 is a view of the rear of the cover of the fuse cutoutdevice shown in Fig. 1, Fig. 3 is an exploded view of a portion of thefuse cutout including the articulated fuse link pull-out means, of myinvention, Fig. 4 is an enlarged sectional view taken on line 4-4 ofFig. 1, Fig. 5 is a side sectional view similar to Fig. 1 showing thedisconnecting device of my invention in the closed circuit position,Fig.

' 6 is a view similar to Fig. 2 showing the rear of the cover includingthe disconnecting blade of Fig. 5, and Fig. 7 is a sectional view takenon line 1-1 of Fig. 5.

Referring now to the drawings, Ill indicates a housing or casing ofporcelain or similar insulating material having an integrally formedelectric creepage barrier l0 which separates two stationary terminalassemblies generally indicated at l I and I2, respectively,mounted-within housing Ill. The upper and lower terminal assemblies Hand i2, except for one additional part associated with the upperterminal assembly II and described hereinafter, are identical "inconstruction and, accordingly, only. the upper one of these terminalassemblies will be described in detail and the corresponding parts ofthe assemblies II and I2 will be designated by the same referencenumerals. Terminal assembly H comprises a U-shapedterminal support l3which is adapted to be cemented into apair of pockets II in the housingI0, only one of which is visible in Fig. 1 since the other isimmediately behind the one shown, which pockets are separated by a finnot discernible in the drawings but which are interconnected by means ofan opening or notch in this separating fin. This interconnection isprovided to facilitate the pouring of the cementing material. which ispreferably. poured hot through the lead entrance opening 16 in housing10. By using a plurality of pockets into which the cementing material ispoured, a stronger construction is provided than if U-shaped terminalsupports l3 were cemented into a single large pocket in housing l0.Terminal assembly I I further includes a terminal I! shown in enlargedsectional view in Fig. 4 and described in greater detail hereinafter. Anextension l8 on terminal I1 is provided so that terminal Il may berigidly supported by U-shaped terminal support I 3 by means of bolt IS.The extension is provided with lugs 20 to engage the edges of theU-shaped terminal support l3 so that the heavy lead coming through leadentrance opening l6 for engagement with terminal II will not cause theterminal to swivel about bolt [9 when the heavy lead is being formed orbent externally of the housing l0.

Terminal assembly I I further includes a pair -of U-shaped contact clips2| which are electrically connected to extension l8 of terminal I 1 v 1through a ring-shaped contact 22, the contact clips being clamped to theextension 8 by bolt 19. In order to insure good contact at contact clips2], I provide 'a plurality of spring strips 23 which are riveted as at24 to U-shaped terminal support l3 and are arranged to provide springbacking means for contact clips 2|. The upper terminal assembly alsoincludes a latch clip 25 which is riveted or fastened in any suitablemanner'thereto and the purpose of which will be set forth hereinafter.

The terminal |1 shown in view in Fig. 4 includes a cylindricallead-receiving portion or passageway 26. A long shoe 21 fits into thelead-receiving portion 26 and is adapted to be depressed into engagementwith the lead, not shown, by means of a pair of screws 28 so as to clampthe lead between one wall of leadreceiving portion 26 and the shoe 21.Suitable means for preventing the screws 28 from being completelyremoved from the lead-receiving portion 26 may be provided. In order tohold the shoe 21 out of the way when putting a large lead intoterminal-receiving portion 26, I provide retracting means comprisingspring 29 which is connected to the shoe 21 by means of a guide pin 30,the lower end of which is spun over as shown at 3| into a depression 32in shoe 21. A suitable washer 33 prevents the spring from dropping intothe opening or aperture 34 in terminalreceiving portion 26, whichopening 34 must necessarily be large enough to allow for angulardisplacement of pin 30. In order to permit spinning over of the end ofpin 30, a suitable opening 35 is provided in the wall of lead-receivingportion 26 diametrically opposite the opening 34 for pin 30.

To the back of the housing or casing l0, there is secured a mounting bar36 for attachment of the cutout to a suitable supporting structure, notshown. This mounting bar 36 is preferably ce mented into an externalrecess 36' in the housing It in the same manner as are terminal supportsl3.

In addition to terminal supports l3 and mounti'ng bar 36, a pair ofhingesupports 31 (Figs. 1, and '1) are cemented into correspondingrecesses 38 in the lower portion of housing I 0, one on either'side ofthe housing. These hinge supports 31, .only'one of which is visible inFig. 1, each include a notch 39 within which suitable trunnions to bedescribed hereinafter are mounted for pivotally supporting the door ofhousing I0.

In order to provide a closure for housing III, I provide a cover or door40, preferably made of a molded insulating compound or the like whichincludes an integral handle or eye 4| which may ,be either graspedmanually or engaged by a suitable form of switch stick to open and closethe cover 40 with respect to housing "I. Cover 40 is provided with apair of recesses 42 only one of which is discernible in Fig. 1, sincethese recesses are in the same horizontal plane. The cover 40 is alsoprovided with a barrier 43 which overenlarged sectional within fuse tube45 includes a fusible element and a strain wire arranged in parallelwith a flexible conductor connected to the lower terminal of the fusibleelement. In Fig. 1, only the flexible conductor 49 of the fuse link isvisible which includes a plurality of cables in order to carry the highcurrents involved. Aswill be understood by those skilled in the art, thefuse including the j fuse tube 45 and the fusible link, only theflexible conductor 49 of which is visible in Fi l, operates on theexpulsion principle to interrupt the circuit therethrough.

The fuse tube 45 is supported on door 40 and is assembled with the doorby thrustin the fuse tube 45 to which upper contact and cap 48 have beenassembled through opening 44 in barrier 43. A pair of pins 56 integrallyconnected to upper fuse contact 46 are arranged to be inserted in therecesses 42 in cover 40 so as properly to position the fuse tube 45.Contact 41 which includes an opening 41' is then slipped over fuse tube45 and the fuse tube is locked into position by means of fuse support 5|having an opening 5| therein which is slipped over the lower end of thefuse laps the creepage barrier l0 and thereby lessens the possibility offlashover between contacts by virtue of hot conducting gases passingtherebetween, having an opening 44 therein which has suflicientclearance to accommodate a fuse tube upper part of fuse tube 45. As willbeunderstood by those skilled in the art, the fuse link mounted tube 45and screwed to the cover 40 as at 52. By allowing a small amount ofclearance between pins 50 and recesses 42 and between opening 44 inbarrier 43, and fuse tube 45, the upper fuse contact 46 may be madeslightly floating on cover 40 so as to line up properly with the contactclips 2| of upper terminal assembly even when the cover 4|! does notsquarely seat in position on housing l0. Fuse support 5| having opening5| therein for accommodating fuse tube 45 is provided with a pair oftrunnions 53 for engaging the notches 39in hinge supports 31, therebyproviding a pivotal support for cover 40 and fuse tube 45.

Lower contact 41 is mounted on fuse tube support 5| by means of apin 54passing through trunnions 53. By allowing suflicient clearance betweenthese parts, contact 41 may have a floating action relative to cover 40so as to line up properly with contact clips 2| of lower terminal=assembly l2. In order to prevent premature disengagement of thetrunnions 53 from notches 39 when opening the door 46 of the fusecutout, I provide on lower contact 41 9, lug 56 which engages with theextension |8 of the lower terminal assembly l2 and effectively preventssuch premature disengagement. Lug 56 is provided with a thumb screw 51extending therethrough and having a substantially rectangular clampingshoe 58 mounted on the otherend of the thumb screw for clamping theflexible conductor or cable 49 against projection 59 integrallyassociated with contact 41. In order to provide good electrical contactbetween contact clips 2'| and contacts 46 and 41, each of the contacts46 and 41 is provided with raised restricted contact surfaces 60 whichare preferably formed of a metal, the oxide of which does notsubstantially interfere with the conduction of current. Silver, forexample, is a suitable metal for such purpose since its oxide isrelatively unstable physically, and consequently, raised restrictedcontacts of silver are very satisfactory although any other suitablemetal may be used.

In order to provide prompt fuse link terminal separation in that rangeof fault current where there is not suificient expulsion action causedby the arc in fuse tube 45, I provide an articulate fuse-link pull-outmeans which takes up a very small amount 'of space and yet whichprovides for a wide separation between the fuse-link terminals. Thisarticulated fuse-link pull-out means comprises a pair of rigid membersor arms 6| and 62. Arm 6| has'a forked portion 63 which is pivotallymounted to support 6| at 64. A suitable spring 66 associated withsupport 64 and shown in the exploded view of Fig. 3 is provided to biasarm 6| in a counterclockwise direction with reference to the view shownin Fig. 1 so as to tend to assume the dotted position shown. Arm 62 isprovided with a drumlike portion 66 which houses a driving spring 61.This drumlike portionis pivotally mounted as at 66 to arm 6| with thespring 61 arranged to tend to cause clockwise rotation of arm 62 aboutpivot 66 with reference to Fig. 1. A suitable stop member 69 is providedon drum 66 of arm 62 to engage with a corresponding stop member I on arm6| to limit the clockwise rotation of arm 62 about pivot 68 and causearm 62 to assume the dotted position indicated in Fig. 1 whenunrestrained by conductor 49. Arm 62 is providedwith a forked end II toaccommodate the conductor 49. When the fuse device of Fig. 1 is loaded,arm 62 is rotated in a counterclockwise direction with reference to arm6| in the manner of a jack-knife moved to the closed position and arm 6|is rotated in a clockwise direction about pivot 64 with reference to theview of Fig, 1. Thereafter conductor 49 is passed within fork H and overdrum 66, as best shown in Figs. 1 and 2, and is clamped between clampingshoe 58 and projection 59 so as to hold the articulated fuse-linkpull-out means comprising arms 6| and 62 in the position indicated inFigs. 1 and 2. With the drum or spool-like portion 66 arranged overspring 61, molten metal contained in the arc blast expelled from thebottom of fuse tube 45 is prevented from injuring spring 61. Also, byvirtue of the double arms 6| and 62, both of which are spring biased,the heavy cables making up conductor 49 are pulled from the end of fusetube 45 at high speed. Since the forked portion 1| of arm 62 will tendto follow the conductor 49 rather than slide therealong upon blowing ofthe fuse, it follows that friction and binding are reduced toaminimurmIn view of the detailed description included above, the operation of myfuse cutout device will be obvious. As soon as the fusible section ofthe link melts, the strong spring pressure applied by springs 65 and 61to arms BI and 62, respectively. causes the remaining portion of thefuse link and particularly conductor 49 to be pulled quickly out of thetube 45 to insure rapid arc interruption even at low current. Afteroperation of the fuse device, the arms 6| and 62 extend downwardly inthe dotted position shown and serve as a very satisfactoryindicatingmeans to show clearly that the circuit is open. By use of suchan articulated pull-out means, a sufficiently long operating stroke isobtained to pull the conductor 49 completely out of the fuse tubewithout requiring any large space within the cutout housing toaccommodate the same in the unoperated position.

The fuse cutout described heretofore may readily be converted to adisconnect type of cutout by replacing door 46 with a door including adisconnecting blade as shown in Figs. 5, Sand '7. The correspondingparts of the housing are identical with those shown in Figs. 1 to 4 andare, ac-

cordingly, designated by the same reference numerals. Referring now toFigs. 5, 6 and 7, I have ing I6 is closed by means of a door or closuremember 12, preferably made of a molded insulating compound or the like,and including an integral handle or eye I3. In thi respect, cover '70indicated a disconnect cutout in which the hous- I2 is substantiallyidentical with cover 46 of Fig. l. Fastened to the lower inside portionof cover 12 as at 14 is a=support 15 substantially identical withsupport 5| of Fig. 1 except that the support is slotted at 16 to permitpivoting of a disconnecting blade 11. Support 15 is provided withtrunnions I8 identical with the trunnions 53 of Fig. 1 which are adaptedto be mounted in the notches 39 of hinge supports 31. Blade 11 ispivotally mounted to support 13 by means of a pin 19 passing throughtrunnions 18. A suitable spring 86' is mounted in a recess 8| in thelower portion of blade TI and presses against pin 19 to tend to biasblade 11 upwardly but to permit a. downward movement of blade 11 forreasons enumerated hereinafter.

As in Fig. 1, in order to prevent premature disengagement of trunnions18 from notches 39 of hinge supports 31, I provide an extension orprojection 82 on disconnect blade 11 which is adapted to engage with theextension l6 of lower terminal assembl |2 s0 that, upon opening the door12 of the disconnect cutout, disengagement of trunnions 18 and notches39 cannot occur until a predetermined opening position of door 12 hasbeen attained.

Disconnect blade 11 is preferably a solid conductor having spacedcontacts 83 and 84 thereon for engaging with the respective upper andlower contact clips 2| of cutout housing i6. In order to insure goodelectrical contact, contacts 83 and 84 are preferably provided withraised restricted contact surfaces 85 similar to the contact surfaces 60of Figs. 1 and 2. r

In order to hold disconnect blade IT in a parallel position with respectto door I2, I provide a knob 86 suitably fastened to door 12 and havingan enlargement 81 thereon for cooperating with a notch 88 in the upperend of disconnect blade 11. As mentioned above. spring 8| tends to biasdisconnect blade 11 in an upward direction to maintain the enlargedportion 81 of knob 86 in the latched or engaged position with respect tothe notch 88 of disconnect blade 11. The disconnect cutout illustratedin Fig. 5 is not designed to open the circuit while the circuit iscarrying full-load current but it will interrupt small currents such asa transformer exciting current.

In order to prevent burning of the contact 85' and associated contactclips 2| under such conditions. disconnecting blade 11 is provided withan arcing tip 89 at the upper end thereof.

When the circuit is to remain disconnected for a time. the conductingdisconnect blade 11 may be moved downwardly upon bodily removal of door72 from housing l6 against the compression of spring 8| to unlatch notch88 from knob 86 and blade 11 may be pivoted to hang downwardly in thedotted position shown in Fig. 5 and the door 12 may be reclosed toprevent snow and ice from entering the housing Ill. The disconnectingblade hanging downwardly in the dotted position shown will provide asuitable indication that the circuit through the cutout is open.

'The contact clips 2| engaging with contacts 83 and 84 maintain theblade and consequently the disconnect door 12 in the closed positionwhen the cutout is arranged for carrying current, However, in order tohold the cutout in the closed position when the disconnect blade 11 isrotated to the dotted position shown and contact clips 2| no longerengage with contacts 83 and 84, I provide contact clip 26 associatedwith terminal assembly H in housing l6 for engaging the enlargement 61of knob 66 and insuring that cover fall within the true spirit and scopeof m invention.

i What I claim as new and desire to secure by Letters Patent of theUnited States is:

1. In an electric disconnect device, the combination of a housing, adoor for closing an open side of said housing, spaced contacts in saidhousing, a support mounted on said door for relating said door to saidhousing, a rigid electrical conduc'tor pivotally mounted on said supportfor interconnecting said contacts in said housing, and

means for alternatively supporting said conductor on said support onsaid door in a position electrically isolated from at least one of saidcon tacts and depending from the bottom of said housing to indicate anopen-circuit condition between the contacts in said housing even thoughthe open side of said housing is closed by said door.

2. In an electric disconnect device, the combination of a housing, adoor for closing an open side of said housing, spaced contacts mountedin said housing, a rigid electrical conductor pivotally supported fromone end of said door, latching means for the other end of said conductorfor holding said conductor in substantially parallel relationship withsaid door, said conductor being so positioned with respect to said doorand said housing as to complete an electric circuit between saidcontacts in said housing when the open side of said housing is closed bysaid door, and means for alternatively supporting said conductor fromsaid door in a position electrically isolated from at least one of saidcontacts and depending from said housing to indicate an open-circuitcondition between the contacts in said'housing.

ternatively supporting said conductor fromsaid door in a positionelectrically isolated from at least one of said contacts anddependingfrom said housing to indicate anopen-circuit condition between thecontacts in said housing.

4. In an electric disconnect device, the combination of a housing, adoor for closing an open side of said housing, spaced contacts mountedin said housing, a rigid electrical conductor pivotally supported at oneend of said door, latching means for the other end of said conductor forholding said conductor in' substantially parallel relationship with saiddoor, means including a. spring associated with the pivotally supportedend of said conductor'for causing said latching means to be operative,saidconductor being so positioned with respect to said door and saidhousing as to complete an electric circuit between said contacts in saidhousing when the open side of said housing is closed by said door, andmeans for alternatively supporting saidconductor from 3. In an electricdisconnect device, the combination of a housing, a door for closing anopen side of said housing, spaced contacts mounted in. said housing, arigid electrical conductor pivotally supported at one end of said door,latching means for the other end of said conductor for holding saidconductor in substantially parsaid door in a position electricallyisolated from at least one of said contacts and depending from saidhousing to indicate an open-circuit condition between the contactsinsaid housing. 5. In an electric disconnect device, the combination ofa housing, a door for closing an open side of said housing, spacedcontact assemblies in said housing, a pair of hinge supports havingtrunnion-receiving notches therein supported in said housing, a membermounted at one end of said door and having a pair of trunnions thereonfor pivotally supporting said door to said casing when said trunnionsengage said trunnionreceiving notches, a rigid electrical conductorpivotally mounted on said member for interconnecting said contacts insaid housing when said trunnions engage trunnion-receiving notches andsaid door closes the open side of said housing, a lug associated withsaid conductor for engaging with one of said contact assemblies toprevent premature disengagement of said trunnions from saidtrunnion-receiving notches upon opening of said door, and means foralternatively supporting said conductor in a position electricallyisolated from at least one of said contact assemblies and depending fromthe bottom of said housing to indicate an open-circuit condition betweenthe contact assemblies in said housing.

6. In an electrical switching device, the combination comprising ahousing, a door for closing an open side of said housing, spacedcontacts mounted in said housing, an electrical conducting meanspivotally mounted on said door and arranged to complete the electricalcircuit between said contacts in said housing when said door is in theclosed position, and means including said electrical conducting meansfor extending outwardly from said housing under open circuit conditionsof said switching device when said door closes the open side of saidhousing to indicate the condition of said switching devce.

BENJAMIN R. HERMANN.

